SHG studies of self-assembled monolayers of subphthalocyanines on gold

Abstract

Self-assembled monolayers of thioether substituted subphthalocyanine [BClSubpc(Sn-C 12 H 25 ) 6 ] were prepared by deposition from solution. The adsorption kinetics of the molecules on gold substrates was characterized in situ and in real time by optical second harmonic generation (SHG). The obtained data have been fitted with three standard kinetic models and best agreement has been found using the first order Langmuir kinetic model. Subsequently, ellipsometry measurements have been performed to determine the thickness of the formed molecular layers. The extracted thickness was 13.0 nm, demonstrating the formation of a monolayer.

Phthalocyanine Derivatives with Eight Peripheral Long‐Chain n‐Alkylseleno Substituents

“…However, product purification is more difficult in this case, and additional work is needed to solve this problem. The use of pure compounds is mandatory for the systematic study intended with these alkylseleno‐substituted macrocycles, which will be investigated in terms of SAM formation on gold in comparison with the corresponding alkylthio‐substituted phthalocyanines, , and subphthalocyanines, of our previous surface science work. The results will be reported in due course.…”

“…The surface chemistry of porphyrins, phthalocyanines and closely related compounds is a burgeoning field, which has experienced tremendous recent development . One aspect, which has been of particular interest to us in this context, is the fabrication of self‐assembled monolayers (SAMs) of such macrocyclic species on gold by chemisorption from solution as a form of nanotechnology , . We have been pursuing a strategy, which is based on metal complexes of phthalocyanine derivatives with eight peripheral β‐positioned alkylthio substituents RS (Figure ), which are conveniently accessible by cyclotetramerisation of the corresponding 4,5‐bis(alkylthio)phthalodinitriles …”